"I didn't know this recording existed," Marsalis said. "And I've listened to a lot of Louis Armstrong. This is a great find - Not so much for the virtuosity of his playing, but for the joy of his presence at that age and at that stage of his life."

Marsalis was "shocked" by the energy and vigor of Armstrong's playing. "I'd heard those songs many times. But that he could play with this type of energy and intensity with that amount of time off. It was shocking."

"Louis Armstrong was one of the greatest human beings to ever set foot on this planet," Marsalis said. "He gave us a healing that still sits with us. Thank you, Pops."